Electrical problems after replacing the alternator

Tiny
COREY22581
  • MEMBER
  • 2006 HYUNDAI ELANTRA
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 114,000 MILES
My alternator went out so I replaced it. After replacing the alternator my low beam headlights won't come on but my high beams work fine and my head unit won't come on. The new alternator does not seem to be charging the battery. If I drive it for about a half the battery starts to die all the lights dim and it won't shift out of first gear. All this happened in a day. I drove it to work this morning perfectly fine also I thought it might be a bum battery. So I took it to AutoZone had it charged and tested the battery is good. I thought it might be a bum alternator they sold me. So I took it back off had him test it in the store and it passed and the fuses for my low beams and my head unit are good.
Thursday, October 31st, 2019 AT 9:05 PM

3 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
This could be due to the alternator they sold you is not equipped to match your vehicle. There are many options including ones with internal regulators and other with clockwise rotation.

I think the best thing to do is hook up a meter to your battery when the vehicle is running. We need to see what the voltage is when it is running at idle and then at 2,000 RPM's.

Let me know what you find and we can go from there.
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Friday, November 1st, 2019 AT 5:21 PM
Tiny
COREY22581
  • MEMBER
  • 2 POSTS
I fixed it. It was the alternator fuse, and for some reason when the old alternator went out it burned out my low beam bulbs and burnt out the fuse in the back of the radio.
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Friday, November 1st, 2019 AT 5:37 PM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Great news. I didn't even think about that. A lot of times when an alternator fails, it sends too much current and can melt and fry stuff.

Thanks for the info. I am sure that will help others that are having similar issues. Thanks again for using 2CarPros.
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Friday, November 1st, 2019 AT 7:43 PM

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